Roving frame cone



May 15, 1934- F. H. MARTIN 1,958,632

ROVING FRAME GONE Filed Oct. 27, 1932 2 Sheets-Sheet 1 INVENTOR.

j@ H' m ATTORNEY.

May 15, 1934. F. H. MARTIN ROVING FRAME GONE Filed Oct. 27, 1932 2Sheets-Sheet 2 INVENTOR. 52D 5+. www,

ATTORNEY.

Patented May 15, 1934 UNITED STATES PATENT OFFC 10 Claims.

This invention relates to the paired cones which form an essential partof roving frames and serve as a variable speed mechanism to transmit tothe bobbins a speed of rotation in excess cf that of the flyer, in theusual bobbin-lead fly frames,

which excess speed is known as the winding speed of bobbin rotation. Asis well-known, the cones are mounted in parallel and reversed relation,the top cone being driven and imparting driving rotation to the bottomcone by a narrow belt or other interposed frictional driving devicewhich is shifted lengthwise of the cones step by step by the rack motionof the tension devices of the frame at the end of the winding of eachlayer jof roving on the bobbin, to compensate for the increased diameterof the bobbin as a result of the winding of such layer and thus toreduce the rate of axial winding rotation of the bobbin to keep theperipheral speed of the wound mass constant and in proper accord withthe rate at which the roving is delivered from the drawing rolls.

Any discrepancies between the rate of delivery and the rate ofwinding-on of the roving result in a change in the tension, which if tootight draws and thins and weakens the roving in uncontrolled manner, orif too slack permits it to contract and thicken under the twist beinginserted so that it becomes oversized, either contingency resulting inserious troubles rendering it difficult or impossible to obtain theessential degree of uniformity in the product.

The paired cones which are thus used to provide the variable speed driveof the bobbins have all been designed on the presumption that thewinding of each successive layer of roving adds a constant amount to thediameter ofthe wound mass, irrespective of the position of such layer inthe sequence of layers from the beginning to the end of the winding, aswould be true in winding wire or other unyielding substance. Theunderlying mathematical relationship between the Whole and the partadded, where the part added remains constant and is added to the wholeover and over again is expressed in the curve known as the hyperbola.Thus this curve forms the basis for the shaping of all known pairs ofroving cones, the values of the curve being divided between the twocomplementary cones at equivalent points to keep the slope of each asgentle as possible for the sake of the belt drive, all as known.

It is well-known that in practice these hyperbolic cones, or moreproperly conoids, do not actually provide a rate of change in theWinding speed that will keep the tension correct throughout the windingof a set oi bobbins from empty to full relation. Thus, with the bestpossible adjustment of twist, tension, and lay, with all relatedmechanism in the best of mechanical condition, such conspicuousdiscrepancies in the tension regularly arise in the course of thewinding as to make it standard practice for the attendant to stop theframe, lift the knock-off latch and move the belt shifter rack by handin the attempt to reestablish approximately correct relationships. Thisprocess of racking is resorted to whenever the need becomes apparent tothe operators eye or touch, ordinarily occurring once or several timesin winding each set of bobbins. Such need for constant supervision andmanual adjustment of the tension to supplement the mechanical orautomatic control supposed to be effected by the cones is a seriousobstacle to production both through cutting down the number of frames anoperator can properly attend, and through requiring stoppage of thespinning while the adjustment is being made, and is furtherobjectionable through causing bad work if the adjustment be improperlymade. In the effort to avoid this objectionable necessity for racking,uniformity in the roving has been sacrificed through inserting an excesstwist and tension, which method has its own drawbacks, perhaps the Worstof which is the inevitable cutting down of the production which comesfrom slowing down the drawing rolls to secure this increased twist.

I have discovered that with the best possible adjustments and conditionsthere is an unfailing tendency for the tension to become too slack at astage early in the winding when the latter is effected by theoreticallycorrect hyperbolic cones, this slackness becoming conspicuous after 15to 20% of the thickness of the nished bobbin has been wound. Thisdeparture from proper tension unavoidably introducing permanentunevenness, may leave its effect on the roving through continuing asslack tension clear through to the completion of the winding, or mayresult in a more or less orderly alternating sequence of successivelythin and thick layers of roving being wound.

I have found that the varying pressure of the presser is probably themost important factor in effecting the growth of the bobbin so as tothrow it out of step with the theoretical rate of growth on which theuse of the hyperbolic cones is predicated. This factor has been totallydisregarded so far as I am aware in designing all known roving cones,because uniformity of strand-thickness has been taken for granted. Yetthis pressure varies within rather wide limits during the building-up ofthe bobbin, being at its maximum when the first layer is wound on thebobbin and being at its minimum when the last or outermost layer iswound, as will be plain from the diagram of Fig. 6. Apparently becauseof the resistance to compression of the rst few layers wound, whichresults from their proximity to the hard and unyielding surface of thebobbin, the forces such as that of the presser which throw the bobbinsize out of step with the hyperbolic cones do not have an observableeiect at first; but their action becomes increasingly apparent after thefirst 10% or 15% of the thickness of the bobbin has been wound,resulting in a gradual compacting or condensing of the wound layerswhich reduces the diameter of the bobbin below the theoretical size andaccordingly produces a cumulative slackness of tension. As iswell-known, this slackness usually attains its maximum when about of thebobbin has been wound. It is to be noted in this connection that theseseveral stages which have been approximately indicated by thepercentages of thickness given, are substantially constant for all sizesof bobbins and of roving being wound,fbecause as constructed therelationship of the presser to its flyer remains substantially constantregardless of the size of the flyer, which varies in accordance with thesize of the full bobbin being wound therewith. It

' is this constancy of relationship which makes it possible to formulatecorrections which are applicable to all types of cones employed inroving frames.

An important feature relating to the practice of my invention is mydiscovery that when the slackness commonly known to occur during theWinding of the earlier portions of the thickness of a bobbin has beencorrected throughmodifying the shape of the cones, the excessive tensionalso commonly arising at the finish of the windbottom cone is too largeand hence is being driven too slowly if it produces a slack tension) yetI do not have to exceed the diameter of the true hyperbolic cones at anypoint and especially at the big end of the bottom cone, in order 5'0"-to keep the tension uniform throughout and to prevent the customaryexcessively tight tension at the end of the winding which follows as aconsequence of intermediate slack tension, and which otherwise wouldseem to call for an in- 'crease in the diameter of the big end of thebottom cone. Thus I am enabled to apply the principles of my inventionto the reshaping of existing roving cones of whatever make or design,applying my improvement thereto by a of simple machining operationinvolving only the moved and replaced in the roving frame than the topcone, the change being merely the matter of a few minutes work.

The invention in its broadest aspect comprises a cone controlling thewinding speed of a bobbin,

.having intermediate portions of its length of a diameter less than thediameter needed to impart a progressive reduction in bobbin rotation asbased on the presumption of equal additions to bobbin diameter asproduced by winding the successive layers. Preferably, the improved conewill comprise a series of contiguous conical frusta, so as to simplifythe mechanical operations involved in its making, instead of thehyperbolic conoidal form heretofore employed. This cone will have a beltengaging surface less in diameter at substantially all points in itslength than that of the hyperbolic conoid conforming to the theoreticalpercentage of increase in bobbin diameter.

An illustrative embodiment of the invention is shown in the accompanyingdrawings, in which,"

Fig. l shows the paired cones as used in a roving frame, the bottom coneof the invention being shown in full lines within the standardequivalent true hyperbolic cone, which is indicated in dotted lines.

Fig. 2 shows certain steps in performing the actual operations of makingthe improved cone.

Fig. 3 is a large scale showing of a portion of Fig. 2 at the top centerof the latter.

Fig. 4 is a hyperbola showing the theoretical rate of increase of bobbindiameter.

Fig. 5 shows a standard flyer in operating relation to its empty bobbin,with a full bobbin indicated in dotted lines.

Fig. 6 is a diagram illustrating the variation in the pressure of thepresser as the bobbin increases in diameter.

One good way of carrying the invention into effect is as follows:

Since the invention is aimed to correct and improve the operation ofroving frame cones,

whose fundamental law of winding in layers is representedby a hyperbola,the casting (if a new cone) or the old roving frame cone, as the casemay be, is rst divided equally into 35 stations, of which the smallextremity is station zero and the large end is station 35, this because35 linches is the usual length of the standard cones. Then thedimensions of the theoretical hyperbola y are applied to the casting orthe cone at stations 0, 5, 25, and 35, as through cutting annulargrooves to the proper depth so that their bottoms lie in the curve ofthe hyperbola and of suiiicient width to operate in, on the orderof 1A;inch, it being understood that this basic hyperbola is calculated withrespect to the complementary top cone, to which a cooperating hyperboliccurvature will have been given, as referred to herein before. Where thecones to be corrected have true hyperbolic outline, this grooving toapply the hyperbola is unnecessary,

as in the case of Figs. 1, 2 and 3.

Starting with the diameter found or thus arrived at at the bottom of theannular groove at station 0 the material of the cone may be cut away ona straight taper such as will exactly coincide at station 5 with thediameter found on the true hyperbolic cone, or in other cases applied asabove to the cone at the bottom of the annular groove here. In otherwords, this first operation produces a section extending from station 0to station 5 which is a true conic frustum, having for its slope asingle straight line, as distinct from the conoidal frustum of the truehyperbolic cone, of which the profile is not a straight line but acurve. As explained later, this step is optional in correcting oldcones, unless desired to counteract belt-slippage.

A similar straight taper is next applied to the cone or casting in suchmanner as to have at its small end this exact diameter of the truehyperbolic cone or of the bottom of the annular groove at station 5, asthe case maybe, and atv its large end the exact diameter of the truehyperbolic cone, or in other cases, of the cone at the bottom of thegroove, at station 25, the beginning and end of such cut and of thestraight lines denoting its course being indicated by the encircledvnumeral l in Figs. 2 and 3. As before, this straight taper,intersecting the theoretical hyperbola at stations 5'and 25, asindicated at a and b in Figs. 2 and 3, gives to this section of the conethe form of a true conic frustum.

Another straight taper is begun at station 21, intersecting the surfaceof the conic section produced by the cut l as indicated at c in Fig. 3,and also intersecting the surface of the theoretical hyperbola atstation 35, at the point d, which as seen before in certain cases liesat the bottom ofthe annular groove formed at this station. Thisoperation is as indicated by the encircled numeral 2 in Figs. 2 and 3,and likewise gives to the larger end of the cone the shape of a trueconic frustum.

Thereafter, another` straight taper is turned down on the surface thusimparted to the cone or casting in such manner that its small endintersects the cut 1 at station 17 as indicated at the point e and hencehas the same diameter as this cut at this station, and also intersectsthe cut 2 at station 27, as indicated at f, having at its large end thedimension of cut 2 at this point. rIhis final cut is indicated by 'theencircled numeral 3.

Obviously, in making a lot'of identical cones, the second and succeedingones of the series may be made by merely duplicating the measurements ofthe rst, as through turning them with the use of a former.

It is found in practice unnecessary to modify the shape of existingcones in regard to the portion of their length extending from station 0to station 5, because the shape of the first ve inches at the small endof all known types of bottom cones used in roving frames departs in soslight a degree from a conic section, and because also the proximity ofthe unyielding surface of the bobbin prevents the pressure of thepresser from throwing the bobbins growth out of step with thetheoretical rate of increase in its diameter expressed by the hyperbola,when the winding is controlled by this portion of the bottom cone. Inevent the diagrammatic showing of the bottom cone in Figs. 1 to 3, inwhich the curvature of the cones has been greatly exaggerated andintensified to make the departures of the invention more conspicuous,and which for the first iive inches of the small end has not beenmodified but is of hyperbolic conoidal shape,

Vile achieved through the practice of the invention is indicated insolid lines.

It is to be noted that all the corrections applied to the theoretical orhyperbolic cone consist in cutting away the material of this hyfvperbolic cone, so that the resulting improved cone has a belt-engagingsurface less in diameter at substantially all points in its length thanthat of the hyperbolic conoid conforming to the theoretical percentageof increase in bobbin diameter. This is because the pressure of thepresser and other factors make it necessary to reduce the angular speedof the bobbin by unequal amounts from the point in the winding wherethese forces make the thickness of the successive layers less than thatof the roving be ing wound, through to the completion of the winding.Thus, the intermediate portions of the length of the improved cone havea diameter less than the diameter needed to impart a progressivereduction in bobbin rotation proportioned to equal additions tobobbin-diameter as produced by winding the successive layers. The basicconcept of the improved cone as thus made becomes a series of trulyconic frusta placed end to end in contiguous relation on a common axis,either with or without the inclusion of the old conoidal frustum at thesmall and less troublesome end of the cone.

The eifect of the presser which makes necessary the modification of thetheoretical hyperbolic conoidal bottom cone is represented graphicallyin Fig. 6. This is a diagrammatic plan view of the standard flyer hshown in operative relation with an empty bobbin z' in Fig. 5. When thebobbin is empty, the presser lc occupies the fullline position, in whichits counter-balancing weight m swings about the axis of the bobbin z' ina circle of radius R, the centrifugal force of the weight moverbalancing the similar force of the presser k and causing the latterto swing inward and press radially against the surface of the firs-tlayer wound on the bobbin i with maximum force. When the bobbin hasgrown to the diameter indicated by the circle n, the weight m` will betravelling about the axis of the bobbin on a smaller circle of radius r,the resultant lessened centrifugal force of this weight having decidedlydiminished the force with which the presser now bears against thesurface of the wound mass n.

Not only does the roving made through the use of cones embodying theinvention show a conspicuous increase in uniformity, but also the use ofthe improved cones usually makes it possible to take out from one to twoteeth from the 1f@ twist gear used, because of the uniformity of tensionattained, and this means an increase in the rate of production of about3% for every tooth removed.

While I have illustrated and described one good method of practising theprinciples of the invention, I am aware that many modifications may bemade therein by any person skilled in the art, without departing fromthe scope of the invention as expressed in the claims. Therefore, 13G Ido not wish to be limited to the specific form shown, or to theparticular details and dimensions of construction thereof, but

What I do claim isz- 1. The method of making paired cooperating ,lroving-frame cones which consists in applying thereto surfaces ofrotation mutually representing complementary portions of a hyperboliccurve, and thereafter modifying the conoidal surface of one thereof bydividing the total length into thirty-five equally spaced stations,applying a straight taper intersecting the hyperbolic conoidal surfaceat or about stations 5 and 25, applying a second straight taperintersecting the iirst straight taper at or about station 21 and the 145hyperbolic conoidal surface at station 35, and then applying a thirdstraight taper intersecting the rst two straight tapers at or aboutstations 17 and 27.

2. In a roving frame, in combination, means for varying the speed ofwinding revolution of the bobbins comprising in combination a drivingcone, a belt, and a driven cone having a beltengaging surface of convexprole, less in diameter at substantially all points in its length thanthat of a hyperbolic conoid conforming to the theoretical percentage ofincrease in bobbin diameter.

3. In a fly-frame, in combination, means for varying the speed ofWinding revolution of the bobbins comprising in combination a drivingcone, a driven cone, and intermediate driving .connections varying thedriving ratio between the two cones, at least one of such cones having asurface of convex profile, less in diameter at substantially all pointsin its length than that of a hyperbolic conoid conforming to thetheoretical percentage of increase in bobbin diameter, to compensate forthe eiect of the presser on the rate of increase of bobbin diameterduring the winding.

4. In a roving frame, in combination, a cone controlling the speed ofWinding rotation of the bobbins, having a series of contiguous conicfrusta of diierent slopes and lengths presenting a prole made up ofsegments of straight lines of substantial length.

5. In a roving frame, in combination, means for equalizing the tensionon the roving which includes the combination with feeding and windingdevices, of a cone having a series of contiguous conic frusta ofprogressively larger size and diminishing angularity of slope withrespect to their common axis. v

6. In a roving frame, in combination, alcone controlling the windingspeed of the bobbins, having a surface of convex prole comprising aseries of conic frusta of different slopes and less in diameter atsubstantially all points than the diam- -eter of the hyperbolic conoidconforming to the theoretical percentage of increase in bobbin diameter,combined with a convex hyperbolic conoid frustum.

7. In a roving frame, in combination, a cone controlling the windingspeed of the bobbins, having a surface comprising a series of conicfrusta of different slopes and lengths presenting a prole made up ofsegments of straight lines of substantial length, combined with aterminal hyperbolic conoid frustum.

8. In a roving frame, in combination, a pair of cones controlling thewinding speed of theA bobbins, one thereof having a series of contiguousconic frusta of different slopes and lengths presenting a profile madeup of segments of straight lines of substantial length, and the otherbeing a hyperbolic conoid.

9. In a roving frame, a cone controlling the winding speed of the bobbincomprising a terminal portion having at substantially all points in itslength diameters adapted to produce a progressive reduction inbobbin-rotation proportionate to equal additions to bobbin diameter asproduced by winding the successive layers, cornbined with intermediateportions of its length of convex prole and of diameters less atsubstantially all points in its length than that needed to impart aprogressive reduction in bobbin-rotation proportionate to such equaladditions.

10. In a roving frame having drawing, twisting and winding devices, thecombination therewith of a pair of cones reducing the angular speed ofthe bobbin in accordance with its actual rate oi increase in diameter asaffected by the i pressure of the presser, one of such cones havingv atsubstantially all points in its length a diameter lying between that ofthe hyperbolic conoid conforming to the theoretical percentage ofincrease in bobbin diameter without regard to the pressure of thepresser, and that of a straighttaper cone of the same end-diameters andlengths as the conoid.

